标签:
Implement pow(x, n).
思路:二分求,注意正负号就是了。
class Solution { public: double cal(double x, int n) { if (n == 0) return 1.0; double tmp = pow(x, n>>1); if (n & 1) return tmp * tmp * x; else return tmp * tmp; } double pow(double x, int n) { if (n < 0) return 1.0 / cal(x, -n); else return cal(x, n); } };
标签:
原文地址:http://blog.csdn.net/u011345136/article/details/44155987